Chitin is a highly insoluble N-acetylated polymer of .beta.-(1,4)-D-glucosamine. Chitosan is an acid-soluble deacetylated form of chitin. Chitin, chitosan, and derivatives thereof are used in a number of industrial applications, including the production of viscosity control agents, adhesives, chromatography carriers, paper-strengthening agents, flocculent agents, food additives, drugs, and cosmetics.
Chitin can be manufactured by the deproteination and decalcification of crab or shrimp shells. Chitosan can then be obtained by deacetylating chitin with a hot alkali solution. This chitosan production process has a number of unfavorable characteristics. For example, the process requires expensive heat energy and caustic alkali, which is a potential health hazard. The process also produces large amounts of waste, thereby necessitating significant disposal costs. In addition, the supply of shrimp or crab shells is highly dependent upon seasonal and environmental factors, leading to unpredictable limitations on production capacity.